Anti-scouring river channel rigid-flexible composite surface protecting device

Abstract

The invention discloses an anti-scouring riverway rigid-flexible composite surface protection device. The device is of a rigid anti-scouring surface and flexible base composite surface protection structure formed by laminating and bonding geotextile, weather-proof geogrids and fine aggregate concrete square cakes. During factory manufacturing, after the geogrids are laid on the surface of the geotextile, the fine aggregate concrete blocks are poured in a matrix arrangement mode, horizontal gaps are reserved between the adjacent blocks, and the rigid-flexible composite surface protection coiled material capable of being curled into coils is formed after maintenance. During construction, the coiled material is released from the top of the trimmed river bank slope, the coiled material rolls and unfolds automatically by means of gravity to cover the slope surface, the adjacent surface protection rolls are in lap joint with each other, and meanwhile, U-shaped steel bars are inserted into the lap joint positions to be anchored in a soil layer so as to prevent displacement. The device resists water flow erosion through the rigid concrete block cake, the flexible base adapts to slope surface deformation, the coiled material can be flexibly folded, unfolded and transported through the gap design, and the flat slope surface can also be horizontally spread. The device has the anti-scouring capability of a rigid protective surface and the construction convenience of a flexible coiled material, can adapt to different river channel slope shapes, is high in durability and low in comprehensive cost, and is suitable for long-term protection of river channel bank slopes.

Description

Technical Field

[0001] The invention relates to the field of river bank slope protection in water conservancy projects, and is an anti-scouring river channel rigid-flexible composite surface protection device, which is particularly suitable for mountain river channel bank slope protection where the river channel bank slope itself is stable but needs to resist water flow scouring. Background Art

[0002] The anti-scour slope protection technology of river bank is mainly to prevent the river flow from scouring and eroding the bank slope, so as to ensure the stability of the river and the safety of the environment on both sides. With the continuous advancement of water conservancy project construction, especially the frequent occurrence of large-volume floods and heavy rainfall, the problem of bank slope scour has become increasingly serious. Effective anti-scour slope protection technology can slow down the impact of water flow on the bank slope, prevent soil loss, and maintain the normal function of water conservancy projects. Common slope protection technologies include plant slope protection, turf slope protection, gabion slope protection and concrete slope protection.

[0003] Plant slope protection technology uses herbaceous plants, shrubs and vines to reinforce the slope soil using the plant roots to prevent water erosion. The fixing effect of plant roots and the buffering effect of stems and leaves can effectively reduce soil loss and is suitable for rivers with slow water flow.

[0004] The turf slope protection technology forms a natural protective layer by laying turf on the surface of the bank slope, using the turf root system to stabilize the soil and reduce water erosion. The turf technology has good water permeability and can slow down the impact of water flow, so it is suitable for places with gentle slopes.

[0005] Gabion slope protection technology uses metal grids to contain crushed stone or gravel and fix it into a stable protective structure. This technology can effectively resist the erosion of large flow of water. The structure is strong and flexible, and is suitable for rivers with high flow rates.

[0006] Concrete slope protection technology uses prefabricated concrete blocks or cast-in-place concrete to reinforce the bank slope to form a solid protective barrier. This method is particularly suitable for river sections with fast flow and steep bank slopes. It has strong anti-scouring ability, but the construction period is long and the cost is high.

[0007] Different anti-scour slope protection technologies are suitable for different river environments. Plant slope protection technology is environmentally friendly and economical. It is suitable for river sections with low flow rate and gentle slope, and can improve the ecological environment. Turf slope protection is similar to plant slope protection, but is more suitable for shallow water areas or relatively gentle slopes. Gabion slope protection is suitable for areas with high flow rate and hard riverbed due to its stable structure and convenient construction. It can effectively deal with more complex scour environments, but the cost is relatively high. Concrete slope protection technology is suitable for river sections with fast flow rate and steep slope. It has strong anti-scour ability, but the cost is higher and has a greater impact on the environment. In practical applications, the selection of appropriate slope protection technology requires comprehensive consideration of factors such as water flow characteristics, geological conditions, construction difficulty and economy to achieve the best protection effect. Summary of the invention

[0008] The above four slope protection technologies have their own advantages and disadvantages: plant slope protection technology and turf slope protection technology are both pure ecological vegetation slope protection technologies, with the best environmental effect, but limited ability to resist water scouring; gabion slope protection technology is a rigid-flexible combination slope protection technology that can effectively resist the scouring of large-volume water flows, but the construction cost is high and the economic advantage is not obvious; and concrete slope protection technology is a rigid slope protection technology with the best protection effect, but the construction cost is also the highest. Therefore, the anti-scouring slope protection of river bank slopes needs to seek a new river slope protection technology that has both good anti-scouring ability and convenient construction and low cost.

[0009] The anti-scour river channel rigid-flexible composite surface protection device of the present invention combines the respective advantages of rigid and flexible structures, and adopts a composite structure composed of geotextiles, geogrids and fine stone concrete blocks. It is convenient for production, storage, transportation and construction, and has good scour resistance and durability.

[0010] Compared with the above four slope protection technologies, the present invention has the following advantages: first, the device is prefabricated in factory production, which is convenient for construction and saves construction time; second, the flexible surface protection can adapt to different slope shapes and can be easily laid and overlapped during construction; third, the rigid concrete surface is hard and rough, with strong anti-scouring ability and durability of up to decades; finally, it has low cost and strong economy, and is suitable for river slope protection projects with various flow rates and geological conditions.

[0011] To achieve the above purpose, the technical solution adopted by the present invention is as follows: The present invention relates to an anti-scour river channel rigid-flexible composite face protection device, which combines the advantages of rigid anti-scour performance and flexible construction convenience, and is formed by stacking and bonding a lower layer of geotextile, an intermediate layer of geogrid, and an upper layer of fine stone concrete blocks. The device ensures that it can achieve efficient protection in river bank slope construction and is easy to promote and apply on a large scale through innovative material combination and structural design.

[0012] During the prefabrication stage in the factory, weather-resistant geogrids are first laid on the flexible geotextile, and fine stone concrete blocks are poured on its surface in a matrix arrangement, with horizontal gaps reserved between adjacent blocks to ensure that the overall structure has flexible curling characteristics in the horizontal direction. After the concrete reaches the designed strength after curing, the composite structure is curled into a cylindrical flexible coil for easy storage, transportation and on-site construction. This prefabrication mode not only improves construction efficiency, but also ensures the consistency of product quality.

[0013] During the construction process, the river bank slope is first repaired to ensure that the slope surface is flat. Then the coil is released at the top of the slope, so that it rolls down and unfolds under the action of gravity, thus covering the slope surface section by section. Adjacent coils are laid in an overlapping manner, and the overlapping width is controlled at 150-250mm to ensure the continuity of the overall protection effect. In order to prevent the device from shifting or lifting under the action of water flow, U-shaped anchor steel bars are used at the overlap for permanent fixation. The anchor steel bars penetrate into the soil layer, with a horizontal section length of not less than 200mm, a vertical section spacing of 500-1500mm, and an anchoring depth of ≥500mm to ensure that the device is stable and has long-term anti-scouring ability.

[0014] First, geotextiles are used as the bottom material, and polyester filament needle-punched nonwoven geotextiles are used to provide strong tensile strength and good water permeability to prevent soil loss on the slope. Polyester filament needle-punched nonwoven geotextiles form a fiber entanglement structure through a needle-punching process, which has both flexible laying adaptability and long-term anti-biodegradation performance. It is a key material to ensure the stability of the bottom layer in the composite face protection device.

[0015] Secondly, the middle layer geogrid is made of biaxially stretched high-density polyethylene, and its tensile strength in warp and weft directions is ≥30kN / m, and the node peeling force is ≥200N, which effectively enhances the stability of the overall structure. Biaxially stretched high-density polyethylene geogrid is made of high-density polyethylene (HDPE) and modified with anti-ultraviolet and antioxidants. Its structural features: the molecular chains are highly oriented during the stretching process to form a uniform rectangular grid, and high peeling strength is achieved at the nodes through melt strengthening. As the middle layer of the composite face protection device, it disperses stress through the mesh interlocking effect to inhibit cracking of the slope; at the same time, it is bonded with the lower geotextile and the upper concrete block to balance the deformation difference between the rigid layer and the flexible slope. Through molecular-level strengthening and structural design, this material has become the core component of the rigid-flexible composite face protection device to achieve the function of "flexible bearing rigidity".

[0016] Furthermore, the thickness of the top layer of fine stone concrete blocks is controlled at 50-80 mm and coincides with the intersection of the geogrid, so that its rigid surface has a strong resistance to water erosion while retaining a certain degree of flexibility to adapt to changes in slope morphology.

[0017] Compared with traditional rigid concrete slope protection or flexible plant slope protection, this device can not only provide long-term and durable anti-scouring ability, but also retain the advantages of flexible structure and easy construction. Its paving method is simple and efficient, does not require large-scale mechanical construction, and is suitable for river environments with different slopes and flow rates. In addition, since the device adopts a factory prefabrication mode, compared with traditional on-site cast concrete slope protection, it greatly reduces the project cost and reduces the damage to the natural environment. Overall, this invention has broad application prospects in the fields of river management, ecological restoration and water conservancy projects. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0019] Figure 1 A structural plan view of a scouring-resistant river channel rigid-flexible composite face protection device provided by the present invention; Figure 2 A cross-sectional view of an anti-scour river channel rigid-flexible composite face protection device provided by the present invention after laying and installation; Figure 3 A flow chart of the operating steps for implementing an anti-scour river channel rigid-flexible composite face protection device provided by the present invention.

[0020] The figure includes: geotextile (1), weather-resistant geogrid (2) and fine stone concrete block cake (3), and also involves U-shaped anchor steel bars (4) and river slope (5). DETAILED DESCRIPTION

[0021] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below with reference to specific diagrams.

[0022] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0023] The following is a detailed description of the implementation of the present invention in conjunction with the accompanying drawings. Figure 1 and Figure 2As shown, the present invention provides an anti-scouring river channel rigid-flexible composite surface protection device, which is composed of three layers of materials, namely, a bottom layer of geotextile (1), a middle layer of weather-resistant geogrid (2), and a top layer of fine stone concrete blocks (3). The implementation operation is divided into two stages: factory prefabrication and on-site construction. Figure 3 shown.

[0024] During factory prefabrication, geogrid (2) is first laid on geotextile (1), and then fine stone concrete blocks (3) are poured on the surface in a matrix arrangement, with horizontal gaps reserved between adjacent blocks (3). After the concrete is cured and formed, the three materials with different characteristics are vertically overlapped and bonded to form a rigid-flexible composite. The composite structure has flexible curling properties in the horizontal direction and can be easily rolled up during construction, making it easy to transport and stack.

[0025] During on-site construction, the river bank slope (5) is first repaired to ensure that the slope surface is relatively flat. The composite roll is then released from the top of the slope surface, and gravity causes it to flip and self-expand and cover the surface of the river bank slope (5) section by section. Adjacent flexible face protection rolls are laid in an overlapping manner, with an overlapping width of 150-250mm. At the overlapping joint, a U-shaped steel bar (4) with a diameter of 10-14mm is driven into the soil layer to ensure the stability of the overlapping joint and prevent the device from shifting. The horizontal section length of the overlapping U-shaped steel bar (4) is not less than 200mm, the vertical section spacing is 500-1500mm, and the anchoring depth is ≥500mm, which can provide long-term fixing force for the face protection device.

[0026] The composite face protection device of the present invention has a rigid and flexible structure, which not only has a rigid anti-scouring ability, but also retains the convenience of a flexible structure during construction. The materials of each layer of the composite device have different characteristics: the geotextile (1) provides strong tensile strength and water permeability, which helps to prevent soil loss; the geogrid (2) provides high tensile strength and node peeling force, which enhances the stability of the structure; the fine stone concrete block (3) has a hard and rough surface, which can effectively resist water erosion.

[0027] This composite device can not only resist decades of water erosion, but also has low cost and strong durability. Prefabricated factory production can ensure the quality consistency of the device and the efficiency of construction. The on-site laying process is simple and can quickly complete the protection of large-area river bank slopes. Compared with traditional rigid concrete slope protection or plant slope protection technology, the present invention provides a more economical, reliable, and easy-to-construct solution that is suitable for the protection needs of various flow rates and river morphologies. Example

[0028] A mountain river is located in the rainy southwest area, with a total length of 12km, an average width of 8m, and a depth of 3-4m. The water flow is turbulent during the flood season, with a flow rate of 3-5m / s. The bank slope soil is mainly sandy clay. Due to long-term erosion by water flow, the bank slope has collapsed seriously, threatening the safety of farmland and villages on both sides. The traditional concrete slope protection scheme was rejected due to the complex terrain, difficult transportation and high cost. Finally, the anti-scouring river channel rigid-flexible composite surface protection device proposed in this patent was adopted for treatment.

[0029] The project adopts a three-layer composite structure design: the bottom layer is polyester filament needle-punched non-woven geotextile with a unit area mass of 450g / m 2 , breaking strength 22kN / m, with both water permeability and tensile resistance; the middle layer is paved with biaxially stretched high-density polyethylene geogrid, with a spacing of 350×350mm, a tensile strength of 35kN / m in the warp and weft directions, and a node peeling force of 250N, which enhances the overall stability; the top layer is poured with C25 fine stone concrete blocks, with a single block size of 300×300mm and a thickness of 60mm, which are precisely aligned with the intersection of the geogrid, and a gap of 50mm between adjacent blocks, which not only retains the flexible curling characteristics, but also forms a rigid anti-scouring surface. The anchoring system uses 12mm diameter hot-dip galvanized U-shaped steel bars, with a horizontal section length of 250mm, a vertical section spacing of 1.5m, and an anchor depth of 800mm in the soil layer to ensure the long-term stability of the device.

[0030] The project implementation is divided into two stages: factory prefabrication and on-site construction. In the factory prefabrication stage, geogrids are precisely laid on geotextiles through an automated production line, and concrete blocks are cast using a mold array. After the curing reaches the designed strength, the composite structure is rolled into a flexible roll with a diameter of 1.5m and a length of 15m. The weight of each roll is controlled within 1.5 tons, which is convenient for truck transportation to mountain construction sites. In the on-site construction stage, the loose soil on the slope is first cleaned and leveled to a slope error of less than 5%. Then the roll is released from the top of the slope, and it rolls and self-expands by gravity to cover the bank slope, with a longitudinal overlap of 200mm and a horizontal flat joint without gaps. U-shaped steel bars are driven into the overlap every 1.5m, and the slope foot and slope top areas are encrypted to 500mm, with an anchor depth of 800mm. During the construction process, the 8-person team laid an average of 500m² per day, which is 60% more efficient than traditional cast-in-place concrete slope protection.

[0031] In order to enhance the ecological benefits, water-resistant grass seeds were sown in the gaps between concrete blocks, and the soil-retaining properties of geotextiles were used to promote the growth of vegetation such as bermudagrass and reeds. After the completion of the project, it has gone through three flood seasons, with no scouring damage to the bank slope and a vegetation coverage rate of 30%, achieving both protection and ecological restoration effects. Compared with traditional solutions, the total investment of the project was reduced by 2.8 million yuan, the amount of concrete was reduced by 3,200 m³, and carbon emissions were reduced by 65%, while protecting the safety of 200 mu of farmland and three villages along the coast.

[0032] The successful experience of this case has been extended to other similar mountain rivers, suitable for earth slopes with a slope of 1:1 to 1:2.5 and river sections with medium and high scour risks with a flow rate not exceeding 6m / s, especially suitable for engineering scenarios that require both rapid construction and ecological restoration. The device solves the contradictions of anti-scour, difficult construction, and high cost through a rigid-flexible composite structure and factory prefabrication mode, providing a standardized solution for the management of small and medium-sized rivers, with significant social, economic and environmental benefits.

[0033] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention. These changes and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A rigid-flexible composite surface protection device for river channel against scour, characterized in that: The device comprises, from bottom to top, a geotextile layer, a weather-resistant geogrid layer and a fine stone concrete block layer, and the three-layer structure is stacked and bonded vertically to form a composite body; the fine stone concrete blocks are cast on the surface of the geotextile and geogrid in a matrix arrangement, and horizontal gaps are reserved between adjacent blocks; the composite body can be rolled into a flexible coil in the horizontal direction, and a continuous rigid anti-scour protective surface is formed after unfolding.

2. The anti-scouring river channel rigid-flexible composite surface protection device according to claim 1 is characterized by: The geotextile layer is a polyester filament needle-punched nonwoven geotextile with a unit area mass of ≥400g / m² and a breaking strength of ≥20kN / m.

3. The anti-scouring river channel rigid-flexible composite surface protection device according to claim 1 is characterized by: The geogrid layer is a biaxially stretched high-density polyethylene grid, with a tensile strength in the warp and weft directions of ≥30 kN / m and a node peeling force of ≥200N.

4. The anti-scouring river channel rigid-flexible composite surface protection device according to claim 1 is characterized by: The plane size of the fine stone concrete block is 30-50 mm smaller than the geogrid grid spacing, the thickness of a single block is 50-80 mm, and the center of the block coincides with the intersection of the geogrid grid.

5. The anti-scouring river channel rigid-flexible composite surface protection device according to claim 1 is characterized by: The overlapping edge of the composite face protection device is provided with U-shaped anchor steel bars with a diameter of Φ10-14mm, a horizontal section length of ≥200mm, and an anchoring depth of ≥500mm; the overlapping width of adjacent face protection rolls is 150-250mm, and U-shaped anchor steel bars are driven into the overlapping joints at a vertical section spacing of 500-1500mm to fix them in the soil layer.

6. The anti-scouring river channel rigid-flexible composite surface protection device according to claims 1-5, characterized in that The implementation steps include: ① factory prefabrication: laying geogrids on the surface of geotextiles, and pouring fine stone concrete blocks in an array; ② curing and molding: concrete curing for 28 days to the design strength; ③ roll material preparation: the composite structure is rolled into a cylindrical flexible roll material and then stacked for storage; ④ on-site paving: the roll material is released from the top of the slope, and gravity expands to cover the slope surface, and adjacent roll materials are overlapped and laid; ⑤ anchoring and fixing: U-shaped anchor steel bars are driven into the overlapped parts at a certain interval to a predetermined depth.

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